Proportional divider and calculator



Nov. 3, 194 DE A. E. LUDWIG 2,300,448

PROPO RTIONAL DIYIDER AND CALCULATOR Filed Dec. 6, 1959 I javvzwz'mv; &% M flnkm f @414.

Patented Nov. 3, 1942 UNITED STATES PATENT OFFICE PROPORTIONAL DIVIDER AND CALCULATOR 9 Claims.

My invention relates to a new and useful instrument for use in all fields of engineering and mechanics and is herein designated a proportional divider and calculator.

The main object of the invention is to provide a device for accurately and efficiently proportioning distances, as for example, locating contour lines in map plotting, measuring on odd scale maps, diversified spacing on drawings and shop layouts, etc. This instrument is further useful as a draftsmans compass. Further objects and the multiple utility of my device are hereinafter fully set forth, reference being had to the accompanying drawing in which:

Fig. 1 is a top view, Fig. 2 a front or face View of Fig. 1, and Fig. 3 is a right end elevation of Fig. 2, showing one embodiment of my device. Fig. 4 is a fragmentary detail View of the cen tral part of Fig. 2 with the upper part thereof in section as between the arrows -t-4 in Fig. l and on the line indicated by the latter and showing a certain modification of detail.

Fig. 5 is a modification of Fig. 2 right end elevation of Fig. 5.

Fig. '7 is an enlarged fragmentary View comprising mainly an elevation of the transversely movable indicator and a portion of the longitudinally movable cross bar and the main bar. Fig. 8 is a sectional view as on line 88 in Fig. '7.

Fig. 9 is an enlarged sectional detail as on line 9-9 in Fig. 4.

Fig. 10 is a top detail View of the flat metal compression spring used in a cross head guide of the device.

Referring to the drawing by reference numerals, with like characters designating corresponding parts in the various figures, I have illustrated my device in a preferred form resemblin in general a well known so-called slide rule, of which the main body is an elongated quadrangular, laminated bar or plate. This bar or plate may comprise a center piece H with front and rear face plates i2 of relatively thin, preferably pure white, material. Said plates l2 are a little wider than the center piece ll thus providing longitudinal recesses in both of the longer edges of the main bar for the purpose of retaining a pair of movable cross-head guides I3 and M of which I3 is the upper guide and I4 is the lower guide. Both said guides are firmly connected at both front and rear by a pair of transverse fiat cross-bars l5, preferably of transparent material, as indicated in Figs. 2 and 8. These cross bars and guides are movable longitudinally of the main bar II and I2, always held in transverse and Fig. 6 a

relation thereto by a spring 36, and one or both carries a removable pointer or indicator member [6, preferably of transparent material, movable transversely of main bar Il-l2 and on its bar IS, with the inner face slightly clear of the ad- J'acent face of plate H! of the main bar. This pointer or indicator member i6, if made of a transparent material will have around opaque dot, ISD, of a diameter approximately equal to the width of lines 20 on face plates Hi. When transverse slide l6 and longitudinal slide l3--M+ I 5 are moved and dot IED coincides with any line 2i] on the adjacent face of plate l2 readings are obtained, as will presently be described (see Fig. 2).

H is a metal end piece, secured as with rivets 18 on the right hand end of the main bar i i-| 2, the said end piece bifurcated upwardly to straddle the bar lI-l2 and below the latter may be pointed as HP or have a short terminus as HT (Fig. 5). In either case the point and inner face of prong HP or terminus HT is in alinement with the initial or first delineation !9 line it being transverse of the main bar.

On front and or rear face of the main bar H-| 2, I provide a series of divergent lines 29, extending from a lower line designated 2! which is parallel to lower edge of the bar, and spaced apart on said line on a predetermined spacing, say between them, starting from the first delineation I9. All said lines terminate on a line designated 22 near and parallel to the upper edge of the main bar, said upper termini spaced apart on said line on a predetermined spacing say /4", between them. Thus the delineations 20 will present the fan like design shown in Figs. 2 and 5.

These divergent lines 26 may be placed on a fiat face or surface as shown in Figs. 2 and 5, on a cylindrical surface with the lines 20 running divergently around the cylinder or on a fiat surface with circular termini lines 2i22, all with the same result, that is a uniform proportioning or dividing of a given distance or measurement into any number of equal spaces.

The lower cross head member [4 is provided with a prong member 23, corresponding to and registering horizontally with prong I'IP, having a vertical (right hand) face 23F arranged to be moved horizontally to and into contact with the inner face of prong HP, and being of course also transverse to the main bar. Said prong 23 may be removably secured to the cross head by means of a set screw 24, and it may be replaced by a pencil lead holder 25 in which the lead point a point in alinement with the inner face MP of the cross head thus comprising means for drawing a circle or arc while using prong I'IP as a center. In other words these latter means comprise, with the main bar, a beam compass. Point 26 herein described as a pencil lead may also represent a removable metal point.

The main use of the prongs HP and 23 is not however for beam compass use but rather to get certain initial measurements or attain certain desired measurements by readings on the divergent lines 2!] determined or attained by manipulation of the cross head and the pointer or indicator l6 thereon, an example of which will presently be fully set forth.

The inner right hand end parts of the upper and lower cross head guides l3 and I4 preferably are made with inwardly directed integral pointers |3P and MP (over the face of the main bar) in alinement with the face |4F or pencil point 26, the tip of said pointers extending to the graduations on the removable scales 3|] and 3| whereon readings are taken separately from, or in conjunction with the divergent lines 2!]. pointer MP may also be used to facilitate reading of the lower termini of the divergent lines 20 or adjacent scale.

Referring now to the transversely movable pointer l6 (preferably of a transparent material), I

the same is movable across the face of main bar as from line 2| to 22 and at its point or thereabout is provided with a minute dot IBD (Fig. 2) or crossed so-called hair lines 29 (Fig. 5) on under side adjacent to face of main bar. pointer I8 if made of an opaque material may be provided with a minute aperture ISA, Fig. '7, through which is sighted any one of the lines 20 upon coinciding therewith or pointer l6 may have a tapered point IGP in line with face HF and point MP of lower cross head guide l4. Said pointer IS with dot I6D, aperture |6A or point IGP may have an enlarging glass as 28 in Fig. 5 for more accurate reading and placement. The reading point |6D, ISA, or IBP is in alinement with points |3P and MP and face HF or 23F.

In Fig. 2 the diverging delineations 20 are designated progressively in multiples of 5 reading from right to left on both the lower and upper lines 2|22, said designated lines may be in other multiples as in Fig. 5, they may also be of a differentiating color to facilitate reading.

Referring to Figs. 5 and 6, removable scale bars 30 and 3| are inserted into the main bar k ||-|2, said scales may have graduation corresponding to the termini of the lines 20 and or the graduations of any common conventional scale for measurements such as full size, one inch equals one foot, one-quarter inch equals one foot, one inch equals ten feet, etc. These removable scales 30 and 3|, any variety of which could be on hand, would facilitate laying out drawings, etc., to any desired scale, and when used in conjunction with the proportional feature of the lines 20, provide a means of dividing a measurement or distance into most any desired number of parts or the multiplying of a measurement or distance. The said scales 30 and 3| are retained frictionally in shallow recesses 3ilA3|A in the main bar and may be fixed by any suitable means, not shown.

As stated my device is highly satisfactory and efficient for a large number of uses, a simple ex- The lower Said ample of its use being considered sufficient to 75 '5 l3 (see Fig. 4).

disclose its practical and diversified usefulness as follows:

Assuming for example, that a drawing is required to be reproduced accurately to a scale /2 larger than the original. In Fig. 2 the distance between and as defined by the two spaced prongs HP and 23 may be a certain measurement, say 2". The pointer I6 is then moved on cross bar |5 until dot |6D coincides with any line (20) of a number divisible by 2 and most convenient. In this case line 10 is used as being most easy to increase by /2 namely 5 points. When dot of i6 has thus been made to coincide exactly with line 10 the cross head is moved to the left until the dot coincides with line 15 which of course is /2 greater than 10. The latter position of the cross head will then be as indicated in dotted lines in Fig. 2 and its point or prong 23 will then be spaced exactly 3 from the stationary prong HP, or the desired greater and proportionate distance with relation to the original measurement of the smaller drawing. Thus any distance originally measured between the points is easily enlarged linearly and accurately, or the process is equally useful for reduction of measurements or distances desired.

As previously described the cross head guide members |3|4 are guided in a shallow groove at both edges of the main bar. Further, the upper of said shallow grooves may also be recessed centrally as 33 (Figs. 34 and 6) for guiding a pair of pins 34 extending inwardly from cross head guide I3. 35 is a metal plate with apertures for said pins 34 to pass through, said plate normally pressed down in the groove to frictionally engage the bottom part thereof, a bow-type fiat metal spring 36 being interposed between said plate and the guide l3 to maintain yieldable compression and friction contact. Said spring is slotted (as at 365) the ends to straddle the pins 34 (see Fig. 10) and at the center is an aperture 36A, through which a thumb screw 31 extends downward to contact plate 35, the said thumb screw being accessible over the cross head guide Thus a simple yieldable spring action is provided to maintain proper tension in the entire cross head at all times, and thumb screw 31 can be used at any time to firmly hold the cross head in any desired fixed position.

In Fig. 9 the member 25, removably securable in the lower cross head, is shown as comprising a split body part with a clamping screw 38 to clamp the pencil-lead 26 in position in a plane such that its point coincides with the inner face |4F of the cross head guide and in alinement with the dot IBD, aperture IBA or point |6P on or in the movable indicator l6.

Referring again to the proportional finding means described it will be readily understood that the proportions may be varied to a very wide range. For example any enlargement from a given layout may be made as from 2 to 6, 1 to 5 etc.

Very accurate readings can be obtained as stated by the use of enlarging, lens, Vernier adjustment with the proportional feature of the divergent lines 2:) thereon, cross-hair lines and equivalent or othen well known devices. For more or less approximate results the point |6P itself may be used moving it to coincide with any one of the divergent lines 20.

I claim:

1. In a proportional divider and calculator a surface containing thereon a group of diverging straight lines extending from regularly spaced termini on one line to correspondingly regular but enlarged spacing of their other termini on another line, said termini lines parallel to each other and in predetermined angular relation to the first one of the diverging straight lines, a cross-head member slidably mounted over said surface and movable in a direction parallel to the termini lines, a pointer member with spot reading means slidably mounted on the cross-head member and movable over said surface in a direction at right angles to the direction of movement of the cross-head member.

2. In a proportional divider and calculator, a main plate provided on each of its two greater surfaces with a group of diverging straight lines extending from regularly spaced termini on a lower line adjacent the lower edge of the plate to correspondingly regular but enlarged spacing of their upper termini on an upper line adjacent the upper edge of the plate, said upper line in parallelism with said lower line and the first of the diverging straight lines on each surface being at right angles to said lower and upper termini lines, a fixed bar and prong member with a face and a point in alinement with the first diverging line, a cross-head member comprising a bar extending over each surface of the main plate with end guides at the lower and upper ends of said bars and a prong part on the lower end guide, and said cross-head member slidably mounted on the main plate and movable in a direction at right angles to the first diverging line and held in parallelism with the fixed bar and prong member, a pointer member slidably mounted on each bar of the cross-head member between the end guides and movable over the two greater surfaces of the plate in a direction at right angles to the direction of movement of the cross-head member, integral pointers one at each side of the lower and upper end guides of the cross-head member and directed inwardly over the greater surfaces of the main plate and extending to the lower and upper termini lines to facilitate reading the respective termini, spot reading means on the pointer members in alinement with the integral pointers on the end guides and the prong part of the lower end guide of the crosshead member to accurately position the pointer member in intersection with any selected one of the diverging lines on the surfaces of the main plate.

3. The structure specified in claim 2, in which the lower and upper edge of the main plate adjacent the termini lines are grooved longitudinally and parallel to the termini lines, each end guide of the cross-head member comprising an elongated piece, both movable simultaneously in their grooves, the bars of the cross-head member rigidly secured to said end guides and positioning the cross-head bars at right angles to the direction of the grooves and termini lines.

4. The structure specified in claim 2, in which the bars of the cross-head member comprise each a transparent flat bar retained in close parallel relation to the main plate surface containing the diverging lines.

5. The structure specified in claim 2, in which the pointer members each comprise a transparent bar slidably mounted on their respective bar of the cross-head member with the surface adjacent the main plate face held in close parallel relation to said face containing the diverging lines, and a spot reading mark on said surface of the pointer member adjacent the main plate face.

6. The structure specified in claim 2, in which the prong part of the lower end guide of the cross-head member comprises in part a removable dual purpose pointer for selectively retaining a pencil lead or metal point either of which is retained with its point coinciding with the point of the fixed bar and prong member when said cross-head member is moved into contact with the face of the fixed bar and prong member which is in alinement with the first diverging line, and said prong pointer in alinement with the integral pointers of the cross-head end guides and the spot reading means on the pointer memher.

'7. A proportional divider and calculator comprising an elongated quadrangular, laminated flat main plate the longer edges of which are grooved inwardly, the outer layers of said laminated plate comprising a white faced material, a transverse bifurcated member straddling and fixed on an end part of said main plate, each exposed main face of the plate provided with a group of diverging lines starting with an initial line exactly transverse of the main plate and successive lines starting from regularly spaced points on a line parallel to the bottom edge of the main plate and diverging on inclined planes to a line parallel to the top edge of the main plate and terminating thereon in predetermined regular but greater spacing than the lower termini of said diverging lines, a cross-head member comprising a pair of cross-head guides movable simultaneously in said grooved edges of the main plate and a transparent cross-head bar traversing each greater surface of the main plate and connecting said end guides, a pointer member slidably mounted on each cross-head bar and movable in a direction at right angles to the grooved edges of the main plate.

8. The structure specified in claim 7, in which said main plate is provided with a row of progressively arranged corresponding numerals adjacent each line of termini of the diverging lines and the latter lines corresponding to said numerals of a difierentiating color to facilitate reading thereof.

9. The structure specified in claim 7, in which said main plate is provided with a longitudinal recess adjacent and parallel to each grooved edge and on each surface containing the diverging lines, and a selective scale member removably retained in each said recess.

DE ALTON LUDWIG. 

